Transformer is a kind of appliance that can 1. increase power 2. increase voltage 3. decrease voltage 4. measure current and voltage Select the correct answer using the code given below :

A transformer is a static electrical device that operates on the principle of electromagnetic induction to transfer energy between circuits [t2][t4]. Its primary function is to alter AC voltage levels. A step-up transformer increases voltage by having more turns in the secondary winding than the primary, while a step-down transformer decreases voltage by having fewer turns [t4][t5]. Crucially, a transformer cannot increase power; according to the law of conservation of energy, input power equals output power (minus minor losses), meaning an increase in voltage results in a proportional decrease in current [t4][t5]. While specific 'instrument transformers' like Current Transformers (CTs) and Potential Transformers (PTs) are used to scale down high values for measurement purposes, the transformer itself is the appliance that performs the voltage change, not the measuring instrument itself [t1]. Therefore, only statements 2 and 3 are correct functions of a transformer.